SECTION 9
STEERING
CONTENTS OF THIS SECTION
Figure Index
Conventional Steering
Specifications
Power Steering
Assembly Manual
Figure Index
Fig. 1 - Steering Gear Cross Section Along Wormshaft
Fig. 2 - Steering Gear Cross Section Along Sector Shaft
Fig. 3 - Conventional Steering Linkage
Fig. 4 - Tie Rod End
Fig. 5 - Pitman Arm Attachment to Relay Rod
Fig. 6 - Checking Pull at Wheel Rim
Fig. 7 - Wheel Alignment and High Point Centering Marks
Fig. 8 - Checking Concentricity of Mast Jacket and Steering Shaft
Fig. 9 - Dash Panel Bracket and Linkage Attachments
Fig. 10 - Steering Wheel - Mast Jacket Clearance
Fig. 11 - Upper and Lower Covers
Fig. 12 - Upper Mast Jacket Clamp
Fig. 13 - Cover Seal and Powerglide Indicator Rod
Fig. 14 - Removing Steering Wheel
Fig. 15 - Removing Pitman Arm from Pitman Shaft
Fig. 16 - Steering Gear Parts Cover
Fig. 17 - Adjusting Lash
Fig. 18 - Removing Sector Shaft from Housing
Fig. 19 - Removing Wormshaft and Ball Nut
Fig. 20 - Replacing Sector Shaft Bushing
Fig. 21 - Removing Wormshaft Bearing Cup
Fig. 22 - Pressing Bearing Cup into Position
Fig. 23 - Filling Ball Circuits in Nut
Fig. 24 - Filling Ball Guides
Fig. 25 - Removing or Replacing Ball Guide
Fig. 26 - Checking Sector Shaft Lash Adjuster End Clearance
Fig. 27 - Installing Sector Shaft Packing and Retainer
Fig. 28 - Mast Jacket and Shifter Tube Assembly - Standard Transmission
Fig. 29 - Exploded View of Mast Jacket and Shifter Tube Assembly
Fig. 30 - Removing Shift Lever and Spring
Fig. 31 - Direction Signal Housing Retaining Screws
Fig. 32 - Removing Locking Plate and Spacer Washer
Fig. 33 - Removing Lever Support Housing
Fig. 34 - Installing Standard Transmission Shifter Tube Assembly to Mast Jacket
Fig. 35 - Tightening Adjusting Ring Screws
Fig. 36 - Neutral Safety-Back-Up Light Switch Wiring Connections
Fig. 37 - Removing Tie Rod End from Steering Arm
Fig. 38 - Separating Relay Rod from Pitman Arm
Fig. 39 - Conventional Steering Special Tools
Fig. 40 - Hydraulic Steering System
Fig. 41 - Control Valve Adapter Assembly
Fig. 42 - Control Valve Connections
Fig. 43 - Hydraulic Pump and Reservoir Mounted to Generator (8 Cyl. Engine)
Fig. 44 - Checking Fluid Level
Fig. 45 - Drain Fluid from Reservoir
Fig. 46 - Removing Hydraulic Pump
Fig. 47 - Hydraulic Pump Assembly
Fig. 48 - Control Valve Removal
Fig. 49 - Unscrew Control Valve
Fig. 50 - Control Valve Disassembled
Fig. 51 - Control Valve Installation
Fig. 52 - Power Cylinder Installation
Fig. 53 - Power Cylinder
Fig. 54 - Power Steering Special Tools
Conventional Steering
INDEX
Figure Index for Conventional Sreering
General Description
Care, Maintenance and Adjustments
Lubrication
Adjustments
Steering Gear
Pitman Arm to Relay Rod Ball Joint
Steering Wheel Alignment and High Point Centering
Mast Jacket and Steering Gear Alignment
Toe-In Adjustment
Major Service Operations
Mast Jacket and Shifter Tube Removal
Steering Gear Removal
Steering Gear Overhaul
Steering Gear Disassembly
Ball Nut Disassembly
Inspection
Repairs
Sector Shaft Bushing Replacement
Wormshaft Seal Replacement
Side Cover Bushing Replacement
Sector Shaft Packing Replacement
Wormshaft Bearing Cup Replacement
Ball Nut Assembly
Steering Gear Assembly
Adjustment on Bench
Mast Jacket and Shifter Tube Overhaul
Disassembly
Cleaning and Inspection
Assembly
Steering Gear Installation
Mast Jacket and Shifter Tube Installation
Steering Linkage Overhaul
Tie Rods
Removal
Installation
Relay Rod
Removal
Cleaning and Inspection
Repairs
Installation
Idler Arm
Removal
Cleaning and Inspection
Repairs
Installation
Troubles and Remedies
Specifications
Figure Index for Conventional Sreering
Fig. 1 - Steering Gear Cross Section Along Wormshaft
Fig. 2 - Steering Gear Cross Section Along Sector Shaft
Fig. 3 - Conventional Steering Linkage
Fig. 4 - Tie Rod End
Fig. 5 - Pitman Arm Attachment to Relay Rod
Fig. 6 - Checking Pull at Wheel Rim
Fig. 7 - Wheel Alignment and High Point Centering Marks
Fig. 8 - Checking Concentricity of Mast Jacket and Steering Shaft
Fig. 9 - Dash Panel Bracket and Linkage Attachments
Fig. 10 - Steering Wheel - Mast Jacket Clearance
Fig. 11 - Upper and Lower Covers
Fig. 12 - Upper Mast Jacket Clamp
Fig. 13 - Cover Seal and Powerglide Indicator Rod
Fig. 14 - Removing Steering Wheel
Fig. 15 - Removing Pitman Arm from Pitman Shaft
Fig. 16 - Steering Gear Parts Cover
Fig. 17 - Adjusting Lash
Fig. 18 - Removing Sector Shaft from Housing
Fig. 19 - Removing Wormshaft and Ball Nut
Fig. 20 - Replacing Sector Shaft Bushing
Fig. 21 - Removing Wormshaft Bearing Cup
Fig. 22 - Pressing Bearing Cup into Position
Fig. 23 - Filling Ball Circuits in Nut
Fig. 24 - Filling Ball Guides
Fig. 25 - Removing or Replacing Ball Guide
Fig. 26 - Checking Sector Shaft Lash Adjuster End Clearance
Fig. 27 - Installing Sector Shaft Packing and Retainer
Fig. 28 - Mast Jacket and Shifter Tube Assembly - Standard Transmission
Fig. 29 - Exploded View of Mast Jacket and Shifter Tube Assembly
Fig. 30 - Removing Shift Lever and Spring
Fig. 31 - Direction Signal Housing Retaining Screws
Fig. 32 - Removing Locking Plate and Spacer Washer
Fig. 33 - Removing Lever Support Housing
Fig. 34 - Installing Standard Transmission Shifter Tube Assembly to Mast Jacket
Fig. 35 - Tightening Adjusting Ring Screws
Fig. 36 - Neutral Safety-Back-Up Light Switch Wiring Connections
Fig. 37 - Removing Tie Rod End from Steering Arm
Fig. 38 - Separating Relay Rod from Pitman Arm
Fig. 39 - Conventional Steering Special Tools
General Description
The regular production steering gear (
fig. 1 and fig. 2) is the
recalculating ball type with a gear ratio of 20:1. This same gear, which
is also used in conjunction with the power steering unit, provides for
ease of handling by having forces transmitted from worm to sector gear
through ball bearings.
The principal working arrangement of the recalculating ball type
steering gear consists of a "ball nut" connected to the
steering worm and in mesh with the sector gear. Precision finished
helical grooves inside the ball nut match helical grooves on the worm,
and it is in these grooves that the ball bearings roll as the steering
wheel is turned. There are two complete ball circuits within the ball
nut. To keep the balls from running out of the end of either circuit,
the nut is equipped with two tubular ball guides, each of which deflects
the balls away from their helical path at one end of their travel,
guides them diagonally across the back of the nut, and returns them to
their helical path between the ball nut and the worm at the other end of
their travel.
The balls within the helical path constitute a thread between
the worm and ball nut, so that when the wormshaft is turned, the nut
moves along the worm. At the same time, the balls roll freely between
the worm and the ball nut, circulating within their closed circuits so
that screw motion is obtained with rolling instead of sliding contact
between parts.
Rugged rack teeth in that portion of the ball nut that faces the
sector and the sector gear teeth are cut so as to provide true gear
action between the sector and ball nut when the ball nut is located at a
slight angle. This type of construction provides a means for backlash
adjustment between the ball nut and the sector by shifting the sector
shaft slightly along its own axis. This is accomplished by means of a
convenient thrust screw, known as a lash adjuster.
The sector teeth are also cut so that when the sector is
adjusted to take out all backlash at the center of travel or straight
ahead position, there will be slight backlash at each end of travel.
Thus snugness of the sector in the rack teeth in a straight ahead
position can be obtained without sacrifice of perfect freedom at extreme
positions, right or left, of the front wheels.
The sector shaft is straddle mounted in antifriction bushings
and a grease seal is provided at the outer end of the shaft.
The worm is integrally welded to the mainshaft and is mounted
between the ball bearings. The bearing at the end of the worm is
adjustable for taking out end play in the wormshaft and for obtaining
proper worm bearing load.
The steering wormshaft passes through a concentric mast jacket
and shifter tube assembly (fig. 28
and fig. 29), which is secured to
the instrument and dash panels but is not rigidly attached to the
steering gear assembly. The shifter tube is free to rotate and slide
within the mast jacket to transmit control forces from the shift lever
to the transmission.
The steering linkage (fig. 3)
is of the relay type, with the pitman arm connected to a relay rod
through an adjustable ball and socket joint. The relay rod is connected
to an idler arm which in turn, is connected to a support bolted to the
frame side rail opposite the steering gear. Pivoting at the connections
at each end of the idler arm is accomplished in rubber bushings.
Connecting the relay rod to the steering arms are two adjustable tie
rods with self adjusting ball and socket type joints (fig. 4)
Care Maintenance and Adjustments
LUBRICATION
The steering gear is filled at the factory with a special
all-season gear lubricant. Seasonal change of this lubricant is
unnecessary and the housing should not be drained. The steering gear
lubricant level should be checked every lubrication period (1000 miles).
Whenever required, additions should be made using a lubricant which, at
low temperatures, is fluid and will not "channel" or cause
hard steering and which will provide satisfactory lubrication under
extreme summer conditions. Steering gear lubricants are marketed by many
oil companies and either "Multi-Purpose" or "Universal"
gear lubricants are satisfactory.
The steering gear linkage should be lubricated every 1000 miles,
with chassis lubricant. Lubrication points and additional information on
the chassis lubricant to be used can be found in Section 0 - General
Lubrication.
ADJUSTMENTS
Steering-Gear
Before any adjustments are made to the steering gear in an
attempt to correct such conditions as shimmy, loose or hard steering and
road shocks, a careful check should be made of front end alignment,
shock absorbers, wheel balance and tire pressure for possible causes.
Correct adjustment of steering gear is very important. While
there are but two adjustments be made, the following procedure must be
followed step-by-step in the order given.
- Disconnect the steering relay rod from the pitman arm by removing
cotter pin from end of relay rod, then removing end plug, spring, spring
plug and ball seat (fig. 3 and fig. 5). Separate relay rod from pitman arm as shown in Figure 38, shifting steering linkage as required to obtain
separation.
- Loosen the pitman shaft lash adjuster screw lock nut and turn the
adjuster screw (fig. 2) a few
turns in a counterclockwise direction. This removes the load imposed on
the worm bearings by the close meshing of rack and sector teeth. Turn
steering wheel gently in one direction until stopped by gear, then back
away about one turn. CAUTION: Do not turn steering wheel hard
against stops when steering relay rod is disconnected as damage to ball
guides may result.
- Using J-544-A Steering Gear Checking Scale (fig. 6), measure pull at rim of wheel which is required to keep
wheel in motion. This should be between 3/8 and pounds. NOTE: When
making this check, it is important that the line of the scale be kept at
right angles to the wheel spoke. If the pull necessary to move the wheel
does not lie between the limits given above, adjustment of worm bearings
is necessary.
- To adjust worm bearings, loosen worm bearing adjuster lock nut and
turn worm bearing adjuster shown in Figure
1 until there is no perceptible end play in worm. Check pull at
wheel rim, readjusting if necessary to obtain proper pull. Tighten lock
nut and recheck pull. If the gear feels "lumpy" after
adjustment of worm bearings, there is probably damage in the bearings
due to severe impact or to improper adjustment and the gear must be
disassembled for replacement of damaged parts.
- After proper adjustment of worm is obtained, and all mounting bolts
securely tightened, adjust lash adjuster screw. First turn the steering
wheel gently from one stop all the way to the other, carefully counting
the total number of turns. Then turn wheel back exactly half way, to
center position. Remove the steering wheel ornamental cap or horn button
and the steering wheel retaining nut and washer. Note position of mark
on end of wormshaft. This mark should be at top of shaft and aligned
with mark on steering wheel (fig. 7).
Turn lash adjuster screw clockwise to take out all lash in gear teeth,
and tighten lock nut. Check pull at wheel rim with checking scale,
taking highest reading of checking scale as wheel is turned through
center position. This should be between 7/8 and 1 1/2 pounds. Readjust
if necessary to obtain proper pull. NOTE: If 1 1/2 pounds is
exceeded, turn lash adjuster screw counterclockwise, then come up on
adjustment by turning the adjuster in a clockwise motion.
- Tighten lock nut then recheck pull as it must lie between specified
limits.
- Reassemble relay rod to pitman arm and adjust as outlined below
under Pitman Arm to Relay Rod Ball Joint. Replace steering wheel
assembly.
Pitman Arm To Relay Rod Ball Joint
- Remove cotter pin from end of relay rod, then using a drag link bit
in end plug slot, tighten end plug until springs are compressed and
plugs bottom (fig. 5).
- Back off end plug 3/4 turn plus amount necessary to insert cotter
pin, then insert pin.
Steering Wheel Alignment and High Point Centering
- Remove steering wheel ornamental cap or horn button and wheel
retaining nut. Set front wheels in straight ahead position. This can be
checked by driving vehicle a short distance to determine steering wheel
position at which vehicle follows a straight path.
- With front wheels set straight ahead, check position of mark on end
of wormshaft designating steering gear high point (fig. 7). This mark should be at the top of the shaft and aligned
with mark on steering wheel. Remove steering wheel, if necessary, and
align mark on wheel with mark on end of wormshaft. See Mast Jacket and
Shifter Tube Removal for a description of the steering wheel removal
operation.
- If gear has been moved off high point when setting wheels in
straight ahead position, loosen adjusting sleeve clamps on both left and
right hand tie rods (fig. 3), then
turn each sleeve an equal amount in the same direction to bring gear
back on high point. CAUTION: Turning the sleeves an unequal
number of turns or in different directions will disturb the toe-in
setting of the wheels.
- Tighten all sleeve clamp bolts.CAUTION: Tie rod clamp
bosses must be below rods to avoid frame interference.
Mast Jacket and Steering Gear Alignment
Misalignment within the mast jacket assembly may cause steering
or shifting interference (assuming the steering gear itself is in proper
adjustment). A few basic causes of such interference together with
suggested checks and adjustments are listed below.
- Steering shaft not aligned with mast jacket and shifter tube
assembly - Check and align steering shaft as described below under
Mast Jacket - Steering Shaft Concentricity. Extreme cases of
misalignment, preventing steering shaft from being centered in
instrument panel opening without bending shaft, may be corrected as
described under Steering Shaft Alignment.
- Interference between steering wheel and top of direction signal
housing - Check and adjust as described under Mast Jacket-Steering
Wheel Clearance.
- Damaged steering shaft, shifter tube or components within the
mast jacket - See Major Service Operations.
MAST JACKET-STEERING SHAFT CONCENTRICITY
- With shifter lever in neutral, check to see if steering gear shaft
is centered in the mast jacket assembly. This may be done by inserting
drill rods or a suitable shimming tool between steering shaft and inner
diameter of adjusting ring at various equally spaced points about the
shaft. Figure 8 shows necessary
dimensional information for this operation. If drill rods are used,
shims may be made from 7/32" diameter rods for standard shift
models or 3/16" diameter rods for Powerglide models, with rods cut
in 1 1/4" lengths.
- If shaft is not centered, loosen the upper dash panel bracket clamp
bolt and the two lower bracket retaining bolts (fig. 9). With shimming tool or drill rods installed (rods evenly
spaced about steering shaft), securely tighten first the upper clamp
bolt, then the two lower bracket bolts. NOTE: It may be necessary to
remove one or more felt seals between steering gear housing and lower
end of mast jacket to insert centering tool or rods. This may be done by
carefully cutting off seals as required, then reinstalling them to shaft
after completion of operation and wrapping them with tape to hold in
place. When performing centering operation, install tool or rods between
steering shaft and adjusting ring I.D., NOT between shaft and shifter
tube I.D.
STEERING SHAFT ALIGNMENT
- Loosen the steering gear to frame bolts and the bolts securing the
lower mast jacket bracket to the jacket and dash panel (fig. 9).
- Install drill rods or shimming tool between steering shaft and
adjusting ring to center shaft in mast jacket as described under Mast
Jacket-Steering Shaft Concentricity.
- Shim between steering gear and frame at bolt holes to maintain this
alignment and tighten gear-to-frame and mast jacket bracket bolts.NOTE:
The bracket upper clamp bolt should be tightened before the lower mast
jacket bracket bolts.
MAST JACKET-STEERING WHEEL CLEARANCE
- Measure gap between top. edge of direction signal housing and
bottom outer edge of steering wheel shown in Figure 10. Clearance should be 1/32" - 9/64".
- To adjust to proper clearance.
- Slide rubber seal on mast jacket (fig.
13) back from instrument panel and remove lower and upper chrome
covers (fig. 11).
- Loosen clamp nuts at dash panel bracket and instrument panel (fig. 9 and fig. 12) just
enough to permit mast jacket to be moved (without rotating) along
steering shaft.
- Locate mast jacket to obtain 1/16" clearance at steering wheel
and tighten clamp nuts at instrument panel, checking to see that key in
clamp is located in keyway in mast jacket.
- Center mast jacket about steering shaft as described above under
Mast Jacket Steering Shaft Concentricity and tighten all dash panel
bracket bolts.
- Install upper and lower covers and slide rubber seal into position.
Toe-In Adjustment
A procedure for adjusting the steering linkage for proper toe-in
setting is described in Section 3.
Major Service Operations
MAST JACKET AND SHIFTER TUBE REMOVAL
- Disconnect all electrical connections and remove the back-up light
switch, where installed, from mast jacket. NOTE: A combination
back-up list neutral safety switch is installed on Powerglide models.
- Remove two rubber cover upper fasteners from inside of dash panel
at mast jacket opening.
- Pry off horn button or ornamental cap and remove horn mechanism.
- Slide rubber seal (fig. 13)
away from covers, then remove lower cover retaining screw and washer and
remove lower and upper covers (fig. 11).
- On Powerglide models only:
- Disconnect ends of indicator rod from indicator lever and shifter
tube and remove rod (fig. 13).
- Remove neutral safety switch.
- Remove transmission control selector plate shown in inset of Figure 9.
- Remove steering wheel nut and washer from end of steering gear
shaft, then using steering wheel puller J-2927-A, thread puller anchor
screws into threaded holes provided in steering wheel hub. Turn center
screw down against centering adapter (fig.
14) and force wheel from steering shaft. Remove spring and spring
seat from end of steering shaft.
- Remove nut, washers and clamp bolt from dash panel attaching
bracket (fig. 9).
- Disconnect transmission control linkage from shifter levers at
swivels. Remove swivels from shifter levers.
- Remove nuts and washers retaining clamp to bottom of instrument
panel and remove clamp and rubber shims (
fig. 12).
- From inside vehicle pull mast jacket assembly carefully off
steering shaft, rotating as necessary to clear dash clamp. Work shifter
levers through dash seal by stretching the seal to clear levers.NOTE:
It may be necessary to pry dash panel clamp apart to free the mast
jacket.
STEERING GEAR REMOVAL
- With mast jacket assembly removed, disconnect pitman arm from
pitman shaft using Pitman Arm Puller J-5504 (fig. 15).
- On Power Steering models remove the generator-to-support and
generator brace bolts and move generator and pump assembly out of
position (without disconnecting hoses) to obtain clearance to remove
steering gear assembly.
- Remove nuts and lockwashers from steering gear to frame bolts and
remove bolts, shims where installed and steering gear.
- Remove the four felt seals from mainshaft of steering gear
assembly.
Steering Gear Overhaul
Steering Gear Disassembly As with any ball bearing unit the
steering gear parts must be kept free of dirt. Clean paper or rags
should be spread on the bench before starting disassembly of the
steering gear. Refer to Figure 16.
- Loosen lock nut on end of sector shaft and turn the lash adjuster a
few turns counterclockwise (fig. 16).
This will remove the load from the worm bearings caused by the close
meshing of the rack and sector teeth.
- Loosen the lock nut on the worm bearing adjuster shown in
Figure 17 and turn the adjuster
counterclockwise a few turns.
- Place a pan under the assembly to catch the lubricant and remove
the three bolts and washers attaching side cover to housing.
- Pull the side cover with the sector and shaft from the housing (fig. 18). NOTE: If the sector does not clear the opening in the
housing easily, turn the wormshaft by hand until the sector will pass
through the opening in the housing.
- Remove the worm bearing adjuster, adjuster lock nut and lower ball
bearing from housing.
- Draw wormshaft and nut assembly from housing (fig. 19). Remove upper ball bearing. CAUTION: Use care that
the ball nut does not run down to either end of the worm. Damage will be
done to the ends of the ball guides if the nut is allowed to rotate
until stopped at the end of the worm.
- Remove lock nut from lash adjuster and unscrew adjuster from side
cover by turning adjuster clockwise. Slide adjuster and shim out of slot
in end of sector shaft.
- Remove sector shaft packing retainer; then remove and discard
sector shaft packing.
Ball Nut Disassembly
As a rule, disassembly of the ball bearing nut will not be
necessary if it is perfectly free with no indication of binding or
tightness when rotated on the worm. However, if there is any indication
of binding or tightness, the unit should be disassembled, cleaned and
inspected as follows:
- Remove screw and clamp retaining ball guides in nut. Draw guides
out of nut (fig. 25).
- Turn the nut upside down and rotate the wormshaft back and forth
until all the balls have dropped out of the nut into a clean pan. With
the balls removed the nut can be pulled endwise off the worm.
Inspection
With the steering gear completely disassembled (fig. 16) wash all parts in cleaning solvent. Dry them thoroughly
with clean rags. With a magnifying glass inspect the ball bearings,
bearing cups, worm and nut grooves and the surface of all balls for
signs of indentation. Also check for any signs of chipping or breakdown
of the surface.
Any parts that show signs of damage should be replaced. Balls
must be replaced with genuine Chevrolet parts made according to
specifications for this steering gear. No non-genuine balls should be
used regardless of grade or quality. Inspect wormshaft seal for defects.
Inspect the sector shaft for wear and check the fit of the shaft
in the housing bushings.
Inspect the fit of the pilot on the end of the sector shaft in
its bushing in the side cover. If this bushing is worn, a new side cover
and bushing assembly should be installed.
Check ball guides for damage at ends where they deflect or pick
the balls from their helical path. Any damaged guides should be
replaced.
Check steering gear wormshaft assembly for bent or damaged
shaft.
Repairs
SECTOR SHAFT BUSHING REPLACEMENT
- Support steering gear housing in an arbor press and press both
sector shaft bushings from housing with Pitman Shaft Bushing Remover and
Replacer J-1614, inserted from lower end of housing as shown (fig. 20).
- Press new bushings into position from each end using the same
sector shaft bushing driver as used for removal. NOTE: Service
bushings are diamond bored to size and require no further reaming.
WORMSHAFT SEAL REPLACEMENT
If the wormshaft seal indicates need of replacement, it should
be removed and a new seal pressed into position in the housing. Pitman
Shaft Packing Retainer Installer J-5813 may be used to install seal.
SIDE COVER BUSHING REPLACEMENT
The entire side cover assembly, including bushing is serviced as
a unit and should be replace where it is desired to replace the bushing.
SECTOR SHAFT PACKING REPLACEMENT
The sector shaft packing must be replaced each time a defective
packing is indicated or the steering gear is disassembled. This
operation is described under Steering Gear Assembly.
WORMSHAFT BEARING CUP REPLACEMENT
- Remove wormshaft bearing cups using Wormshaft Bearing Cup Remover
J-5822 with Slide Hammer J-2654A (fig.
21).
- Press new bearing cups into position using Installer J-5755 (fig. 22).
Ball Nut Assembly
- Place the wormshaft flat on the bench and slip the nut over the
worm with the ball guide holes up and the shallow end of the rack teeth
to the left from the steering wheel position. Align the grooves in the
worm and nut by sighting through the ball guide holes.
- Count 27 balls into a suitable container. This is the proper number
of balls for one circuit. Drop counted balls from container into one of
the guide holes while turning the worm gradually away from that hole.
Continue until ball circuit is full from bottom of one guide hole to
bottom of the other or until stopped by reaching the end of the worm.
NOTE: In cases where the balls are stopped by the end of the worm,
hold down those balls already dropped into the nut with the blunt end of
a clean rod or punch (fig. 23)
and turn the worm in the reverse direction a few turns. The filling of
the circuit can then be continued. It may be necessary to work the worm
back and forth, holding the balls down first in one hole then the other,
to close up the spaces between the balls and fill the circuit completely
and solidly.
- Lay one-half of the ball guide, groove up, on the bench and place
the remaining balls from the count container in it (fig. 24).
- Close this half of guide with the other half. Hold the two halves
together and plug each open end with vaseline so balls will not drop out
while installing guide.
- Push the guide into the guide holes of the nut (fig. 25). This completes one circuit of balls. If the guide does
not push all the way down easily, tap it lightly into place with the
wooden handle of a screwdriver.
- Fill second ball circuit in the same manner.
- Assemble the ball guide clamp to the nut, being sure to use a
lockwasher under the clamp screw, then tighten the screw securely.
Check the assembly by rotating the nut on the worm to see that
it moves freely. Do not rotate the nut to the end of the worm threads as
this may damage the ball guides. If there is any "stickiness"
in the motion of the nut, some slight damage to the ends of the ball
guides or to other gear components may have been overlooked.
Steering Gear Assembly
After a major service overhaul where all of the original factory
installed lubricant has been washed out of the steering gear assembly,
the threads of the adjuster, side cover bolts and lash adjuster should
be coated with a suitable nondrying, oil resistant sealing compound such
as Permatex No. 2. This is to prevent leakage of gear lubricant from the
steering gear assembly. The compound should not be applied to female
threads and extreme care should be exercised in applying this compound
to the bearing adjuster, as the compound must be kept away from the
wormshaft bearing. Also apply grease to the worm bearings, pitman shaft
bushings, and ball nut teeth.
- With wormshaft seal, bushings and bearing cups installed and ball
nut assembly installed on wormshaft, slip upper ball bearing over
wormshaft and insert wormshaft and nut assembly into housing, feeding
end of shaft through upper ball bearing cup and seal (fig. 19).
- Place ball bearing in adjuster cup and install adjuster and lock
nut in lower end of housing.
- Assemble the lash adjuster with shim in the slot in the end of
sector shaft. Check the end clearance which should not be greater than
.002" (fig. 26). For the
purpose of adjusting this end clearance, a steering gear lash adjuster
shim unit Part Number 605142 is available. It contains four shims-.063",
.065", .067" and .069" thick.
- After lash adjuster end clearance has been adjusted, start sector
shaft pilot into bushing in side cover. Then, using a screwdriver
through the hole in cover, turn lash adjuster in a counterclockwise
direction to pull sector shaft pilot into its bushing as far as it will
go.
- Rotate wormshaft by hand until ball nut is about in the center of
travel. This is to make sure that the rack and sector will engage
properly, with center tooth of the sector entering center tooth space of
the nut.
- Place a new gasket on side cover, then push side cover assembly
including sector shaft into place (fig.
18). After making sure there is some lash between rack and sector
teeth, assemble and tighten side cover bolts.
- Soak new sector shaft packing in engine oil to lubricate it; then
install it in packing retainer. Use a new retainer if necessary.
- Place Pitman Shaft Packing Protector J-5787 over end of sector
shaft, then slide packing and retainer over protector and press into
position with Installer J-5813 (fig.
27).
Adjustment on Bench
- Tighten the worm bearing adjuster until all wormshaft end play has
been removed. Then tighten the lock nut.
- Install the steering wheel on the wormshaft temporarily. Carefully
turn the steering wheel all the way in one direction and then turn back
about one turn.
- Using a J-544-A Steering Gear Checking Scale at right angles to one
spoke at wheel rim, measure the pull required to keep the wheel in
motion. This should be between 3/8 and 5/8 pounds. If necessary, adjust
the worm bearing adjuster until proper pull is obtained.
- Turn the steering wheel from one stop all the way to the other,
counting the number of turns. Then turn the wheel back exactly half the
number of turns to the center position and mark the wheel at the top or
bottom.
- Turn the sector lash adjuster screw (
fig. 17) clockwise to remove all lash between rack and sector teeth.
Tighten the lock nut. NOTE: Be sure adjustment is not changed while
tightening the lock nut.
- Using J-544-A Steering Gear Checking Scale, check pull at rim of
steering wheel. Take highest reading on scale as wheel is pulled through
center position. This should be between 7/8 and 1 1/2 pounds.
- If necessary, readjust lash adjuster screw to obtain proper pull.
Tighten lock nut to 10-15 ft. lbs. torque and again check pull.
- Fill the assembly with steering gear lubricant to the level of the
filler plug hole and replace filler plug.
Mast Jacket and Shifter Tube Overhaul
Disassembly
Refer to figure 28 and
figure 29.
- Slide rubber grommet back from lever support housing, drive out
shift lever pin and remove shift lever and anti-rattle spring (fig. 30).
- Remove single screw and clamp at location where wiring enters mast
jacket.
- Remove the three direction signal housing retaining screws
indicated by arrows in Figure 31
and remove direction signal housing. It will be necessary to shift
position of direction signal controls to gain access to the retaining
screws. CAUTION: Withdraw housing with care to avoid damage to
horn and direction signal wiring connections.
- Remove locking plate and spacer washer (fig. 32).
- Remove lever support housing (fig.
33).
- Remove tanged washer (fig. 29)
from mast jacket. This washer may have adhered to the lubriplate on
bottom of lever support housing removed in step 5.
- Reverse mast jacket and loosen retaining bolts on adjusting ring
while holding ring to release compression of spring slowly. Remove
adjusting ring. On Powerglide models remove spring from end of shifter
tube.
- On standard transmission models remove the two shifter levers and
spacer from end of shifter tube assembly.
- Remove shifter tube assembly by pulling it out from end of mast
jacket.
Cleaning and Inspection
- Clean all metal parts in cleaning solvent and dry them with
compressed air.
- Inspect transmission control lever housing for burrs, scratches and
wear. NOTE: The clearance is critical between the shifter tube
assembly and the lever support housing. There must be no interference
between these two working parts and any excessive clearance must be
corrected by the installation of new parts.
- Inspect steering shaft bearing in direction signal housing. The
bearing may be replaced by prying out of position and installing a new
bearing and horn wire assembly.
- Inspect direction signal wiring connections and switch.
- Check direction signal lever for smoothness of operation and
freedom from bind. Replace defective parts.
- Inspect shifter levers and shifter tube assembly for worn or
damaged parts. The shifter tube assembly must be replaced as a unit in
event of worn or damaged component parts. NOTE: The shifter tube
assembly on standard transmission models consists of the tube, spring,
keys, felt seal and washers. On Powerglide models the shifter tube
consists of an integral shifter lever and a felt seal.
- On Powerglide models inspect indicator rod clip to see that it is
anchored in the two holes in shifter tube and firmly clipped to the
tube.
Assembly
- On standard transmission models line up the lower key and washer
tang of the shifter tube assembly (fig.
34).
- Generously lubriplate all keys and small diameter ends of the
shifter tube.
- Insert shifter tube into mast jacket from lower end of mast jacket.
On standard transmission models, align washer tang in slot provided in
mast jacket (fig. 34). On
Powerglide models install return spring to lower end of shifter tube and
slide against shifter lever.
- On standard transmission models only:
- Lubriplate and install second and third shifter lever on shifter
tube. A "U" is stamped on this lever for identification.
- Lubriplate and install spacer on tube with ramped edge away from
shifter lever.
- Lubriplate and install first and reverse lever on shifter tube. An
"L" is stamped on this lever for identification purposes.
- Lubriplate and place adjusting ring in lower end of mast jacket
over shifter tube.
- On standard transmission models, place a .010" feeler gauge
between the second and third shifter lever and spacer, then apply a
force sufficient to push the adjusting ring into the mast jacket and up
against the .010" feeler gauge. While holding adjusting ring in
position, tighten the three adjusting ring bolts (fig. 35). Remove feeler gauge.
- On Powerglide models, push adjusting ring into mast jacket bolt
slots as far as possible to compress the return spring, then tighten the
three adjusting ring bolts.
- Reverse mast jacket and working from the top end install tanged
washer (fig. 29), resting it on
the three tabs protruding inward and keyed in the slot provided in the
jacket.
- Lubriplate inner diameter of lever support housing and install
housing, fitting keyway in housing over key on shifter tube (fig. 33).
- Carefully feed direction signal and horn wires through lever
support housing and into wiring opening at upper end of the mast jacket,
then down through mast jacket and out lower wiring opening.
NOTE: The use of a leader wire, first passed between the mast jacket
and shifter tube and through each opening, then secured to the wire
ends, will facilitate this operation. Lift lever support housing off
most jacket and shifter tube as required to gain access to upper wiring
opening in mast jacket.
- With lever support housing installed, install spacer washer and
locking plate in bayonet slots in mast jacket. Place direction signal
housing in normally installed position on mast jacket to check alignment
of attaching screw holes in housing and locking plate.
- Install direction signal housing retaining screws, locating key in
housing in mast jacket keyway.
- Check end play between lever support housing and direction signal
housing. End play should be .004"-.009". If not within
specified range, remove direction signal housing and locking plate, then
install proper size spacer washer to give .004"-.009" end
play. Reinstall locking plate and direction signal housing and recheck
end play. NOTE: Four thicknesses of spacer washers (.035", .039",
.043", .047") are available, with the largest washer
identified by a single notch or drilled hole, next largest by two
notches or drilled holes, etc.
- Lubriplate the anti-rattle spring and place it on end of shift
lever, then position shift lever in housing and install pin. Slide
rubber grommet into position over pin and against housing.
- Install wiring clamp over opening where wiring enters mast jacket.
Steering Gear Installation
- Place the four felt seals over mainshaft and slide against steering
gear housing.
- Insert end of mainshaft through dash panel opening and position
steering gear assembly on frame. Install bolts, lockwashers and nuts
through bracket. NOTE: Shims may be placed between steering gear and
frame as required to center steering shaft in instrument panel opening.
- Connect pitman arm to pitman shaft.
- Install mast jacket and shifter tube assembly as described below.
Also install generator and pump assembly on Power Steering models.
MAST JACKET AND SHIFTER TUBE INSTALLATION
- Slip assembled mast jacket over steering shaft and feed it downward
to approximate location, rotating as required to provide clearance for
the shifter levers and other projections at dash panel and dash panel
clamp. The rubber seal at the dash panel opening must be stretched to
clear shifter levers.
- Position upper mast jacket clamp with upper and lower rubber shims
installed (fig. 12) over retaining
bolts so that key in clamp engages keyway in bottom of mast jacket and
clamp is centered in instrument panel opening. Install clamp washers and
nuts and tighten nuts just enough to-hold key in keyway (to prevent
rotation of mast jacket) and still permit mast jacket to be moved along
steering shaft.
- Install steering wheel, horn mechanism and horn button or
ornamental cap, aligning steering wheel with mark on end of steering
shaft.
- Grasp mast jacket assembly and pull assembly back along steering
shaft toward steering wheel. Locate assembly 1/16" from steering
wheel by placing feeler gauge or 1/16" shim stock between top edge
of direction signal housing and bottom outer edge of steering wheel
(shown in Figure 10). With
assembly located in this position, tighten clamp nuts below instrument
panel.
- Install dash panel attaching bracket clamp bolt, washers and nut.
- With shift lever in neutral, check to see if steering gear shaft is
centered in the mast jacket assembly. This may be done by inserting
drill rods or a suitable shimming tool between steering shaft and inner
diameter of adjusting ring as described previously under Mast
Jacket-Steering Shaft Concentricity. If shaft is not centered, loosen
the dash panel bracket clamp bolt and the two lower bracket retaining
bolts (fig. 9). With shimming tool
or drill rods installed (rods evenly spaced about steering shaft),
securely tighten first the upper clamp bolt, then the two lower bracket
bolts.
- Connect transmission control rods to shifter levers. On Powerglide
models install the transmission control selector plate shown in the
inset of Figure 9.
- With shift lever in Neutral position install back-up light and
neutral safety switch where applicable.
- Position rubber seal and cover to dash panel and install upper
fasteners.
- Connect horn wire and, where applicable, direction signal, back-up
light and neutral safety switch wiring, by connecting matching colors at
the connectors. CAUTION: Where equipped with a combination
back-up light neutral safety switch, it is imperative that wires be
connected to proper switch terminals as illustrated in Figure 36.
- After completing installation, check steering and shifting for
bind. Also check neutral safety and back-up light switch, where
applicable for proper operation. It may be necessary to loosen the
neutral safety switch attaching screws and shift position of switch to
obtain proper operation.
Steering Linkage Overhaul
Tie Rods
There are two tie rods used on all model passenger cars. Each
tie rod is of three piece construction, consisting of the tie rod and
two tie rod end assemblies. The ends are threaded into the rod and
locked with clamps. Right and left hand threads are provided to
facilitate toe-in adjustment and steering gear centering.
The tie rod ends used (fig. 4)
are self adjusting for wear and require no attention in service other
than periodic lubrication and occasional inspection to see that ball
studs are tight. Replacement of tie rod ends should be made when
excessive up and down motion is evident or if any lost motion or end
play at ball end of stud exists.
Removal
- Remove cotter pins from ball studs and remove castellated nuts.
- To remove outer ball stud, tap on steering arm at tie rod end with
a hammer while using a heavy hammer or similar tool as a backing (fig. 37). If necessary pull downward on tie rod to remove from
steering arm.
- Remove inner ball stud from relay rod, using same procedure as
described in Step 2.
- To remove tie rod ends from tie rods, loosen clamp bolts and
unscrew end assemblies.
Installation
- If tie rod ends were removed, install ends on tie rod making sure
both ends are threaded an equal distance into the tie rod.
- Make sure that threads on ball studs and in ball stud nuts are
perfectly clean and smooth. Install neoprene seals on ball studs. NOTE:
If threads are not clean and smooth, ball studs may turn in tie rod ends
when attempting to tighten nut.
- Install ball studs in steering arms and relay rod.
- Install ball stud nuts, tighten securely and install cotter pins.
Lubricate tie rod ends.
- Adjust toe-in as described in Section 3. NOTE: Before locking
clamp bolts on tie rods, make sure that the tie rod ends are in
alignment with their ball studs (each ball joint is in the center of its
travel). If the tie rod is not in alignment with the studs, binding will
result. Also, tie rod clamp bosses must be below tie rods to avoid frame
interference.
Relay Rod
Removal
- Remove inner ends of tie rods from relay rod as described under Tie
Rod-Removal.
- Remove cotter pin from end of relay rod at pitman arm ball stud
attachment.
- Using a drag link bit, remove end plug from socket and remove
spring plug and outer ball seat from relay rod (fig. 5).
- Detach relay rod from pitman arm (
fig. 38) and remove inner ball seat, plug and spring from relay rod
(fig. 5). Shift steering linkage
as required to free pitman arm from relay rod.
- Remove cover and seal from pitman arm.
- Remove cotter pin and nut from relay rod end of idler arm.
- Remove relay rod from vehicle.
Cleaning and Inspection
Remove accumulated grease and dirt from assembly and inspect for
damage or excessive wear.
Repairs
Pitman arm ball seats may be replaced if inspection shows
necessity.
The Idler Arm to Relay Rod bushing may be replaced by pressing
out old bushing and pressing in new bushing. Note side of rod which
bushing shoulder is against and install new bushing in same manner.
Installation
- With wheels in a straight ahead position, place relay rod over
idler arm, then install and tighten nut to 70 ft. lbs. Advance nut just
enough to align castellation with cotter pin hole and install pin.
- Install new seal and cover over ball at end of pitman arm.
- Install inner spring, plug and seat to pitman arm end of relay rod.
- Raise end of rod and install on pitman arm.
- Install outer ball seat, spring, plug and end plug.
- Tighten end plug until springs are compressed and plugs bottom,
then back off 3/4 turn plus amount necessary to insert cotter pin.
Insert cotter pin to lock adjustment.
- Install tie rod ends to relay rod as previously described under Tie
Rods.
- Lubricate tie rod ends and pitman arm to relay rod ball joint.
- Adjust toe-in (see Section 3) and align steering wheel as described
previously in this section under Steering Wheel Alignment and High Point
Centering.
Idler Arm
Removal
- Remove cotter pins and nuts from ends of idler arm and remove relay
rod from idler arm.
- Remove idler arm from idler arm bracket. Cleaning and Inspection
Remove accumulated grease and dirt from assembly and inspect for damage
or excessive wear.
Cleaning and Inspection
Remove accumulated grease and dirt from assembly and inspect for
damage or excessive wear.
Repairs
If inspection shows a faulty bushing, press out old bushing and
press in new bushing.
Installation
- Position idler arm over idler arm bracket and install nut but do
not tighten.
- Install relay rod to idler arm and install nut but do not tighten.
- With wheels in straight ahead position and steering gear on high
point, tighten idler arm to bracket nut and relay rod to idler arm nut
to 70 ft. lbs. Advance both nuts just enough to align castellations with
cotter pin holes and install pins.
Troubles and Remedies
Symptom and Probable Cause
Probable Remedy
Hard Steering
a. Lack of lubrication.
a. Lubricate steering gear, tie rod ends, steering relay rod ball
joints and steering knuckle joints.
b. Pitman shaft to relay rod ball joint
b. Readjust ball joint.
c. Underinflated tires.
c. Inflate tires to recommended pressure.
d. Improper adjustment.
d. Adjust according to instruction.
e. Interference between steering shaft and mast jacket assembly
caused by misalignment,
bent steering shaft or damaged parts
within the mast jacket assembly.
e. Adjust or replace parts as required.
Loose Steering
a. Improper adjustments.
a. Adjust according to instructions.
b. Loose pitman shaft to relay rod ball joint.
b. Adjust ball joint.
c. Worn steering knuckle ball joints.
c. Replace steering knuckle ball joints.
d. Worn pitman shaft bushings.
d. Replace bushings.
Specifications
Gear Ratio - 20:1
Type - Recalculating Ball
Number
Balls Used - 54
Lash Adjustment or High Point - 7/8 to 1 1/2 lbs.
End Clearance-Lash Adjuster to Sector Slot - 002" max.
Worm
Bearing Adjustment - 3/8 to 5/8 lbs. to keep wheel in motion
Power Steering System
INDEX
Figure Index For Power Steering System
Description and Operation
Power Steering Generator
Recirculating Ball
Hydraulic Steering Mechanism
Hydraulic Pump and Reservoir
Hydraulic Steering Maintenance
Care, Maintenance and Adjustments
Fluid Level
Bleeding Hydraulic System
Pump Belt Tension
Checking Pump Pressure
Steering Wheel Alignment
Major Service Operations
Reservoir and Pump Assembly
Removal
Disassembly
Cleaning and Inspection
Assembly
Control Valve
Removal and Disassembly
Cleaning and Inspection
Assembly
Power Cylinder
Removal
Inspection
Seal Replacement
Trouble Diagnosis
Hard Steering
Excessive Play or Looseness in Steering Mechanism
Low Oil Pressure
Poor Centering or Recovery on Turns
Oil Leaks
Figure Index For Power Steering System
Fig. 40 - Hydraulic Steering System
Fig. 41 - Control Valve Adapter Assembly
Fig. 42 - Control Valve Connections
Fig. 43 - Hydraulic Pump and Reservoir Mounted to Generator (8 Cyl. Engine)
Fig. 44 - Checking Fluid Level
Fig. 45 - Drain Fluid from Reservoir
Fig. 46 - Removing Hydraulic Pump
Fig. 47 - Hydraulic Pump Assembly
Fig. 48 - Control Valve Removal
Fig. 49 - Unscrew Control Valve
Fig. 50 - Control Valve Disassembled
Fig. 51 - Control Valve Installation
Fig. 52 - Power Cylinder Installation
Fig. 53 - Power Cylinder
Fig. 54 - Power Steering Special Tools
General Description
Chevrolet Power Steering equipment on passenger cars, consists of a
recalculating ball type steering gear and linkage to which a hydraulic
power mechanism has been added as part of the steering linkage. The
hydraulic mechanism furnishes additional power to ASSIST the manual
operation so that the turning effort at the steering wheel is greatly
reduced.
The power steering equipment is designed to reduce steering
effort but not to remove the so called "feel" of steering.
With Chevrolet Power Steering, the hydraulic assistance is zero up to a
pull of about 3 pounds at the rim of the steering wheel and the steering
of the car is entirely normal. At this 3 pound load, the hydraulic
system starts to assist the driver's effort and from 3 to 8 pounds pull,
the input effort is proportional to the force necessary to turn the
front wheels. The 8 pound load is sufficient to turn the front wheels
with the car standing still which means the hydraulic system is doing
about 80% of the work of steering.
In addition to assisting the driver in steering the car, Power
Steering greatly reduces the effort required in parking. The oil filled
hydraulic cylinder absorbs road shocks when driving over rough roads,
railroad tracks, etc. This permits the wheel in the driver's, hand to
remain steady, reduces driver "fatigue" and permits many miles
of driving without tiring.
POWER STEERING GENERATOR
A special generator is used with new cars equipped with power
steering. On these models, the power steering pump is mounted on the
commutator end frame and is driven by the splined armature shaft which
extends from the generator.
Generators of this type use ball bearings at both end frames and
all parts have close tolerances in order to provide for the proper
alignment between the generator and the power steering pump. Improper
alignment of the generator and power steering pump may cause a noisy
generator and pump assembly. Improper alignment may result from careless
handling of the generator assembly (resulting in deformed parts), worn
bearings, careless assembly of the pump to the generator, or other
similar items.
Power steering pumps are sealed to prevent leakage of fluid. One
of the seals used for this purpose mounts on the polished surface (1/2"
diameter) of the generator shaft extension. Damage to this surface
(which is machined to very close limits) or damage to the seals during
reassembly of the pump to the generator may result in loss of fluid from
the power steering pump.
Lubrication required on the generator is the same as for the
standard installation.
Recirculating Ball
The steering gear used with Power Steering is the same
recalculating ball type as used on regular production jobs.
HYDRAULIC STEERING MECHANISM
The hydraulic power steering mechanism consists of an engine
driven oil pump delivering oil at a pressure of 750 pounds per square
inch, an oil reservoir, a double-acting hydraulic power cylinder, and a
control valve (fig. 40).
The hydraulic power cylinder assembly is mounted on a bracket on
the relay rod at one end and to another bracket on the frame of the
vehicle.
HYDRAULIC CONTROL VALVE
The hydraulic control valve is attached to the left end of the
steering relay rod (fig. 40) and
is operated by the pitman arm in the following manner:
The pitman arm ball stud is retained in a sliding bearing sleeve
inside the steering linkage tube. Protruding from the ball seat
adjusting nut is a long valve shaft (fig.
41). The spool of the control valve is attached to this shaft so
that any movement of the sliding bearing sleeve is transmitted to the
control valve spool. The spool is restricted to a movement of .050"
travel to the right and left from its centered position by a spacer
between the control valve housing and adapter housing and by the correct
adjustment of the ball stud adjuster. A steel pin (fig. 41) locks the ball stud adjuster to the sliding bearing
sleeve. The spool assembly has two annular grooves which connect three
annular passages inside the valve housing. The valve spool member is
centered and restrained from actuation on the valve shaft by a
pre-loaded spring. It is necessary to overcome the pre-loaded of the
spring before the valve spool can be moved in either direction. When
there is sufficient resistance to rotation of the steering arm developed
at the front wheels, continued turning of the steering wheel will result
in an axial movement of the valve shaft, thus overcoming the pre-load of
the spring. This axial movement is due to the hook-up from the pitman
arm (fig. 42). When the valve
spool assembly is in the centered position, the oil from the hydraulic
pump flows through the center passage of the valve body, through the
annular grooves in the spool to the annular passages in the housing and
then back to the pump.
When axial movement of the spools occurs with a three pound
effort on the steering wheel, the direct circuit of the pump is
interrupted by shutting off both of the direct return passages. The oil
is then forced to travel to one end of the hydraulic power cylinder to
move the cylinder axially on the piston shaft. At the same time the
opposite end of the power cylinder is open to the pump return line and
permits oil at this end to return through the control valve to the pump
reservoir.
Hydraulic Pump and Reservoir
The oil pump, a vane type pump, is mounted on the engine in
position to be driven by a splined extension of the generator armature
shaft (fig. 43).
The pump houses a serrated driving hub or rotor in which ten
vanes slide radially outward to contact the hardened and ground inside
surface of a cam ring. As the shaft and rotor rotate, centrifugal force
and fluid pressure against the inner ends causes the vanes to follow the
cam contour of the ring. The contour of the ring is so shaped that two
opposing pumping chambers are formed. In each pumping chamber, the
increasing and decreasing pockets formed between the rotor, vanes, and
ring, propel the oil from the entrance to the exit ports of the pump.
The pump contains a combination overload relief valve, which is
set to open at 750-P.S.I. at 170°F and a flow control valve which
recirculates oil within the pump as required to regulate the output
volume between 1.1 gal. per minute at idling speed to 1.8 gal. per
minute at approximately 3600 RPM.
The reservoir encloses the pump cover assy. (fig. 43) and provides a reserve supply of oil to assure complete
filling of the hydraulic system. An air chamber in the upper part of the
reservoir and a vented cover attachment provide for the escape of any
air that may be introduced into the system.
HYDRAULIC STEERING MAINTENANCE
Hydraulic Steering Maintenance can be covered in three
categories that generally will include any complaint on the operation of
the unit. These three categories, leaks, noise and hard steering, if
properly handled will correct the majority of complaints that may be
encountered regarding the unit's operations.
Care, Maintenance and Adjustments
Cleanliness is a highly important factor in the service of the
power steering unit. If dirt enters the hydraulic system it will cause
noise, leaks or improper operation. When working on a power steering
unit be sure to completely clean the outside before disassembly. Be sure
the bench is free of dirt, then lay the parts on clean paper. Careful
thought to cleanliness while disassembling and reassembling the power
unit will prevent having dissatisfied owners and a job that must be done
over.
LEAKS
If the complaint is oil loss in the power steering unit, the
following steps should be performed. First, wipe the complete unit dry.
This includes the pump, hoses, power cylinder, and control valve. Then
fill the reservoir, start the engine, operate the steering unit and
observe where the leak occurs. The position of the leak will then give
an indication of the cause.
A possible place for leakage would be at the pump, involving
either the reservoir to pump body seal or the pump drive shaft oil seal.
In the case of pump leakage the repair is fairly simple requiring very
little time to replace the seals. Other leaks may require removal of the
unit from the car and more involved service. Improperly installed seals
is a major cause of leaks. Damage to "O" ring seals will cause
leaks if the housings have sharp edges which cut the "O"
rings. Sharp edges should be removed with a fine stone and new seals
installed.
NOISE
When the complaint is excessive noise it is sometimes hard to
isolate the sound. Following is a quick check to determine whether or
not the steering unit is at fault. Disconnect the pump drive belt and
operate the car. If the noise is no longer present then make the power
steering unit the next check.
CAUTION: Do not operate the engine too long with the
belt disconnected since the water pump is also driven by this belt and
the engine may become overheated.
Another good thing to remember is never diagnose a power
steering complaint without first checking fluid level and drive belt
tension. Either may cause noises and malfunctions which could
conceivably be blamed on the steering unit. When checking fluid level,
be sure bubbles are not present in the fluid. If bubbles are found, the
bleeding procedure outlined under "Bleeding Hydraulic System"
should be performed.
Another cause of noise in the pump can be a sticky valve which
will produce a buzzing sound. This can be determined by checking for
excessive pump pressure with oil pressure gauge, Tool J-5176, outlined
under "Checking Pump Pressure."
Obstructions in the hydraulic system will also cause a noise.
For instance, a slight burr on the edge of one of the valve spool lands
or a hose restriction will cause a noise on turns. Removal of the burr
with a fine stone or replacement of the hose will be necessary for
correction.
If belt noise, possibly accompanied by a knock or steering wheel
oscillation, is present on extreme turns, it's reasonable that improper
pump belt tension is the cause.
HARD STEERING
Dirt in the system has been found to be a cause of hard steering
as greater effort is required to reposition the spool and bring the
power steering into operation. The repair will be a complete cleaning of
the hydraulic system. A pump relief valve stuck in the open position can
be the cause of hard steering as there will be zero pump pressure. This
can easily be checked by using oil pressure gauge J-5176.
Fluid Level
- Check oil level in the reservoir by removing the reservoir dip
stick to determine oil level as indicated by fluid showing on the dip
stick (fig. 44).
- Fill to level with automatic transmission fluid "Type A"
bearing an "AQ-ATF" number. This is the same oil as available
for Powerglide transmissions and is available through Chevrolet Dealer
and Oil Company filling stations. Total in system is 1 1/2 pts.
BLEEDING HYDRAULIC SYSTEM
After a pump or control valve has been installed or a
disconnected oil line is reconnected, the air that entered the hydraulic
system must be bled out, otherwise noisy and unsatisfactory operation
will result. The following procedure should be used to bleed the
hydraulic circuit:
- Fill oil reservoir to proper level and let oil remain undisturbed
for about two minutes.
- Raise front end of vehicle so that wheels are off the ground.
- Start the engine and run at idle for two minutes.
- Increase engine speed to approximately 1500 RPM.
- Turn the wheels (off ground) right and left, lightly contacting the
stops.
- Lower the car and turn the wheels right and left on the ground.
- Recheck for leaks.
- Check oil level and refill as required.
PUMP BELT TENSION
Adjustment
- Loosen the outer bracket to generator bolt and retaining bolt on
the generator rear brace (fig. 43).
- Pull the generator out from the engine with all slack taken out of
the belt.
- Tighten the retaining bolts.
- Push in on the belt midway between the water pump and generator
pulleys with light push.
- If tension is correct there will be 5/16 inches of deflection on 6
cylinder and 13/16 inches on 8 cylinder with a light push at this point.
CHECKING PUMP PRESSURE
- Disconnect the pressure line at the pump connection (smallest, top
line). CAUTION: Some fluid will leak out when the line is
disconnected so provision must be made to collect this drainage.
- Install checking gauge tool J-5176 (with gauge valve closed) on the
pump and hose connection. NOTE: Adapter kit J-5900 must be used to
adopt pressure gauge to pump.
- Open the gauge valve and run engine at idle.
- Turn wheels (on ground) against stops. Pressure should not be less
than 750 psi.
- If pressure is less than 750 psi, slowly close gauge valve
observing gauge for pressure increase. Pressure will increase as valve
is closed if pump is good. CAUTION: Do not leave valve closed
for more than 15 seconds.
- If pressure does not increase when the valve is closed, difficulty
is in the pump, which must be removed for service.
- Shut engine off, remove gauge and valve, reconnect hose to pump if
pressure is O.K.
- Bleed hydraulic system of air as outlined under "Bleeding
Hydraulic System."
STEERING WHEEL ALIGNMENT
Refer to Section 9. Steering Wheel Alignment.
Major Service Operations
Reservoir and Pump Assembly
Removal
NOTE: Omit steps 1 and 2 on 8 cylinder models.
- Loosen generator to bracket retaining bolts and remove fan belt.
- Pull the generator all the way out from the engine.
- Place a container under the pump and disconnect the hydraulic lines
from the pump allowing the oil to drain out of the reservoir into the
container (fig. 45).
- Remove the retaining bolts from the pump to generator and generator
rear brace on 8 cylinder models and remove the pump from the vehicle (fig. 46).
- Complete draining the remaining oil from the pump reservoir before
disassembly.
Disassembly
- Remove the two retaining bolts and sealing washers from pump
reservoir to pump cover assembly (fig.
47).
- Remove the reservoir from the pump assembly.
- Remove the oil filter spring retainer from the pump cover assembly.
- Remove the spring retainer and plate from the pump cover assembly.
- Remove plug and "O" ring, flow spring and pressure relief
valve assembly from the pump cover assembly.
- Remove the three retaining bolts from the pump cover assembly.
- Remove the pump cover from the pump body assembly and remove the
oil filter and retainer.
- Remove the cam ring, pump rotor and vanes.
- Remove the pressure plate from the pump cover assembly.
- Remove and discard the "O" rings from the pump cover, cam
ring, and pump body.
- Remove and discard the generator shaft oil seal from the pump body
assembly.
Cleaning and Inspection
- Wash all parts in cleaning solvent and wipe dry with a lint free
cloth.
- Inspect the fit of vanes in rotor. Vanes must slide freely, but
snugly in slots. Tightness may be relieved by thorough cleaning or
removal of irregularities.
- Inspect flat faces of pressure plate, cam ring, pump cover, rotor
and pump body. These faces may be repaired by lapping until smooth and
flat, after which all lapping compound must be thoroughly washed away.
- Inspect cylindrical surface of pressure relief control valve and
check fit of pressure relief control valve in pump cover. Slight
irregularities may be corrected by polishing.
Assembly
- Lubriplate and install new "O" rings in the pump cover,
on the cam ring, and in the pump body.
- Install the rotor and vanes on the pump body with wear pattern or
beveled edge of vanes against cam ring inner diameter.
- Install the alignment sleeve in the cam ring and install the cam
ring on the pump body. CAUTION: The wider edge of the cam ring
is the correct side to the pump body. Be certain to align bolt holes in
the cam ring to pump body bolt holes. The rotor should be installed with
the rounded side of the splines toward the generator end of the pump.
- Install the pressure plate in the pump cover.
- Install the filter retainer and oil filter on the pump cover.
- Install the pump cover assembly and three retaining bolts to the
pump body.
- Install the plunger and flow spring in the pump cover assembly.
- Install the plug and "O" ring assembly, cover plate, and
retainer spring.
- Install the oil filter retainer spring in the pump cover.
- Install the reservoir, two retaining bolts, and two sealing
washers. NOTE: The brass fitting seats are of the pressed in type
and are replaceable in the event of a fitting leak by tapping threads in
the hole of the seat and then pulling the seat by using a bolt threaded
into the tapped out seat and a flat washer and nut as an extractor.
- When installing new seats, align the seat in its bore and press it
into place using the correct hose or tube fitting as a pressing tool.
- Install pump on vehicle and fill and bleed system as outlined under
"Care, Maintenance and Adjustments."
Control Valve
Removal
- Raise the front of the vehicle off the floor and place it on
stands.
- Loosen the relay rod to control valve clamp (fig. 48).
- Disconnect the two pump to control valve hose connections and allow
fluid to drain into a container, then disconnect the two remaining valve
to power cylinder hoses.
- Remove the retaining nut from the ball stud to pitman arm
connection and disconnect the control valve from the pitman arm.
- Turn the pitman arm to the right clear of the control valve and
unscrew the control valve from the relay rod (fig. 49).
- Remove the control valve from the vehicle.
Disassembly
- Remove dust shield (1) (fig. 50)
from the control valve housing (2).
- Remove retaining pin and nut (3) from the valve shaft.
- Remove the retaining bolts connecting the valve assembly housing to
the adapter assembly housing and separate the two assemblies.
NOTE: Valve spool remains in the housing when the two assemblies are
separated, because the seal at the end of the spool will not allow spool
removal other than from the end of the housing.
- Remove the spring thrust washer (7), spring (8), flat washer (9),
vee seal assembly small washer and spacer (15) from the valve shaft.
- Remove the ball stud cover (13) (fig.
41) from the adapter assembly housing (11).
- Push the ball stud (8) to the end of the adapter housing and remove
the lock pin (4).
- Remove the threaded ball plug adjuster (3) and valve shaft (1).
- Remove the ball seat plug (5) and spring (6).
- Remove the ball seats and ball stud.
- Remove the bearing sleeve (10).
Inspection
- Wash all metal parts in solvent cleaner and dry them with a lint
free cloth.
- Inspect all parts for scratches, burrs, distortion, evidence of
wear and replace all worn or damaged parts, including mating parts where
necessary.
- Replace all seals, gaskets, covers with approved service parts.
Assembly
- Replace the ball seat (9) (fig.
41) in the bearsleeve (10) and insert the sleeve in the housing
(11).
- Insert the ball stud (8) in the sleeve.
- Install the remaining ball seat (7), spring (6) and spring seat (5j
in the bearing sleeve. CAUTION: This is the heavier of the two
springs used in the control valve.
- Install the valve shaft (1) in the adjuster (3) and screw the
adjuster into the bearing sleeve. NOTE: The adjuster should be
tightened until bottoms, and should then be backed off 1/4 turn plus or
minus amount necessary to insert lock pin in nearest hole. CAUTION:
Be sure ball seats remain in correct position, otherwise there will be
insufficient clearance to correctly install the retaining pin.
- Install the ball stud cover (13).
- Install the washer (2) fig. 41
and annulus spacer (15) fig. 50
on the valve shaft.
- Install the vee seal block (14) fig.
50 and ring assembly (10, 11, 12, 13)
fig. 50.
- Install the annulus washer, spring and spring thrust washer (7) fig. 50. CAUTION: Chamfer side of the thrust washer to be
toward spool side.
- Install the spool valve assembly and retaining nut. CAUTION:
The spool valve is installed with the vee seal at the threaded end of
the valve shaft.
- Tighten the retaining nut to 25 in. lbs. with a torque wrench and
install the retaining clip. CAUTION: Be sure all parts including
spring, are correctly located before tightening.
- Insert the assembled valve and adapter assembly into the valve
housing and install the two retaining bolts and lockwashers.
- Fill the end area with GM 4617-M grease and install the valve
housing dust cover.
Installation
- Install the control valve on the relay rod (fig. 51) so that the distance from center of control valve ball
stud to the center of the tie rod end ball stud measures approximately 3
5/8".
- Tighten the control valve clamp. NOTE: The clamp securing the
control valve to the relay rod end should be positioned before
tightening so that it will not interfere with the steering linkage.
- Reconnect the four hydraulic hoses to the control valve.
- Fill the system with type "A" fluid and bleed out air
using the procedure outlined under "Care, Maintenance and
Adjustments."
Power Cylinder
Removal
- Disconnect the two hydraulic lines (5) (fig. 52) connected to the power cylinder and drain fluid into a
container.
- Remove retaining nut, washer, and rubber grommet from power
cylinder rod to the brace attached to the frame.
- Remove the cotter pin, retaining nut, flat washer and bolt from the
end of the power cylinder where it is fastened to the relay rod bracket.
- Remove the power cylinder from the vehicle.
Inspection
- Inspect the seals for leaks around the cylinder rod and if leaks
are present replace the seals, using the following procedure:
- Use a hook tool and remove the retaining ring (fig. 53).
- Remove the wiper ring.
- Remove the back up washer.
- Remove the back up ring seal.
- Remove the seal. NOTE: The piston rod seal should not be
removed unless there are signs of leakage along the piston shaft at the
shaft seal.
- Examine the brass fitted hose connection seats for cracks or damage
and replace if necessary.
- For service other than seat or seal replacement, replace the power
cylinder.
Installation
- Install the power cylinder on the vehicle by reversing the removal
procedure.
- Reconnect the two hydraulic lines, fill the system with fluid and
bleed out air using the procedure outlined under "Care, Maintenance
and Adjustments."
Trouble Diagnosis
This section will cover only those causes of trouble which may
be due to the hydraulic power steering mechanism. Before assuming that
the hydraulic power mechanism is at fault, make sure the mechanical
components are in good condition. The mechanical items include: front
wheel alignment, tire condition and pressure, wheel bearing adjustment,
lubrication and adjustment of steering linkage, and proper alignment of
steering gear in mounting to eliminate bindings.
1. HARD STEERING
To determine whether hard steering actually exists, place car on
a clean, dry floor, apply brakes, and with engine idling, turn wheel to
the extreme right and left and hold against the stop momentarily in each
direction several times. This will bring the oil temperature to
approximately 170°F which is operating temperature. Apply Steering
Wheel Checking Scale, J-5178 (15 lbs.) to a spoke at rim of steering
wheel and check the pull required to turn the wheel steadily with gauge
held at 90 degrees to the spoke. If the pull required to turn the wheel
exceeds 10 pounds, check the following causes.
Possible Causes
- Generator drive belt loose.
- Low oil level in reservoir.
- Air in hydraulic system.
- Insufficient oil pressure.
- Steering adjustment tight.
2. EXCESSIVE PLAY OR LOOSENESS IN STEERING MECHANISM
Possible Causes
- Loose worm thrust bearing adjustment.
3. LOW OIL PRESSURE
If it is believed oil pressure is low, the pressure should be
checked as outlined in "Care, Maintenance and Adjustments"
using pressure gauge, J-5176.
Possible Causes
- Generator drive belt loose.
- Low oil level in reservoir.
- Pump mechanical difficulty-possibly caused by:
- Relief valve; improper adjustment, weak relief valve spring or
relief valve stuck open.
- Control valve stuck or broken flow control spring.
- Worn rotor parts.
- Pressure loss in steering control valve, possibly caused by
sticking valve spool or discharge valve stuck open.
- Pressure loss in power cylinder, possibly caused by leaking seal.
- External or internal oil leaks.
4. POOR CENTERING OR RECOVERY ON TURNS
Possible Causes
- Valve spool sticking in valve housing.
- Binding of steering shaft.
- Loose worm thrust bearing adjustment.
- Sticky cylinder assembly.
5 OIL PUMP NOISY
Possible causes
- Improper oil level.
- Air in system.
- Reservoir air vent plugged.
- Sludge or dirt in pump.
- Pump bearings, shaft, vanes or other rotating parts worn or
damaged. Sticking pump vanes also a possibility.
6. OIL LEAKS
External-Possible Causes
- Loose connections at hose unions or oil pipe elbows.
- Loose connection or faulty "O" rings in pump.
- Hose leaks.
Internal-Possible Causes
- Leaking housing.
- Cylinder seal leaking.
Assembly Manual
Steering Mechanism
Steering Linkage
Steering Gear
Steering Wheel
Steering Gear Clamp
Steering Column and Clutch Rod Dash Seal